19. b2c3  19... a7b6 A calm move, improving the bishop's position. Definitely not an easy move to play, 20. f3d2 Carlsen sacrifices the d3-pawn with check $1 One way to set this up would be to get the king to b2 first. 20... b6c5 Moving the bishop again is too much. 21. h4f6 